birdcage pitch?

[justpianos at our.net.au]

Holly,
Recently I was approached by a customer wanting a quote on repairing a
Lindner piano. She told me that other tuners had refused to look at the
piano, so I made some investigations, to see what I could do. Here’s what
I found.
The Lindner piano was a clever design that fell foul of poor materials.
The Rippen company originated in The Hague, west of Holland, where they
built pianos the classical way. After World War II the company moved to
Ede. They bought an old factory hall, extended it and started building
pianos in a new way. In those post-war years there was a huge demand for
pianos, but most people did not have much to spend. Rippen decided to
develop a "low cost" instrument, and they were successful. They were also
assembling and selling the Thomas organ, which originated in the USA.
During the 1960s Ireland had lots of unemployed, and the Irish government
was looking for investments in order to create more jobs. They published a
bill in which they declared that in Shannon, near the local airport,
foreign companies could achieve quite substantial tax reductions, if only
this would lead to a certain amount of local jobs.
Rippen was already selling pianos in the USA, using the Thomas organ
connection, but pianos being heavy, had to be shipped by boat, which made
it necessary to take care of sea-packaging, and so on.
They had a brain-storm: if they could make a lightweight piano they could
ship it by air. And if they produced it at Shannon the investment would be
low, and for a nice number of years the tax reductions would be
profitable. So they started the development of the "plastic piano". They
used a frame of aluminium tubes welded together, and they replaced as much
of the wooden parts as possible by plastic, ending up with an instrument
of only 75 kilos.  Since the keyboard could be turned downwards inside the
chest they were able to ship two pianos almost in the space normally used
by one. They could then send them everywhere, as long as an airplane could
land.
Only the plastic parts were produced at Shannon, normal parts were
purchased from external suppliers, and Renner even developed a special
action mechanism. The main factory at Ede in the Netherlands supplied some
parts as well.
You might be interested to know that Rippen, in their post-war models,
never did use a "rast" (those posts of 4 x 4 inches). They glued and
screwed the pinblock onto the plate, so all the strength had to come from
the cast iron frame.
The sound boards of all Rippen/Lindner pianos were made out of three
layers, cross-glued: a triplex. One true advantage: it could not crack,
although these Lindner models had quite limited tonal qualities.
It is not know how many instruments were produced at Shannon. In Ede the
maximum output was 18 instruments per day, 5 days a week.
Rippen went broke in the year 1987.

Generally Lindner pianos are worthless now as most of the action is made
of plastic and practically impossible to repair when it goes wrong. Most
Lindners are at an age where they are rapidly disintegrating, hence
utterly worthless as a piano, although when they are working they have a
reasonable touch. No replacement parts are available and most times the
piano is not worth the trouble to repair.
Normally keyboard keys can be lifted out without any problem. The plastic
keys of the Lindner snap in, and thus the keys cannot be removed by
pulling them away: they need to be unlocked. However, often these keys
will come out just by pulling, but the clips will easily break.
Provided the keys are still whole you've got a chance of repairs. But
whatever you do, don't try to glue the plastic keys - it simply won't
take. Super glue, epoxy, Airfix - none of it works. I'm sure there's a
clever plastic welding glue or system that might work - but the first
question would have to be WHY! You can actually borrow the parts you need
to get the middle going from the extreme ends. What's the old saying,
"nobody plays these notes anyway"?
You may need a mixture of hammer flanges (they are a modular snap in job
that often doesn't snap anymore) and the spring steel balance pin
thingees. All of these bits are interchangeable (which is part of the
basically clever idea behind the poor execution*).
Do the repairs first – there is a chance that while you're tuning more
bits will break - this is the only benefit of this whole thing - you won't
have nearly as much of the piano to tune once you're done. Or sell it to
another owner of one of these gems so that they have spares - it's a bit
like owning an old Citroen/Peugeot/Morris/Austin – you never own one - you
need at least three to keep one on the road! The broken key clips seem a
common problem.
It is interesting that the front key dip is adjustable individually, from
under the key bed.
Nobody seems to have invested in injection molding tools for
re-manufacturing the clips, but an easy and reliable way to repair these
pianos is to weld the clips. The plastic of the clips seems to be Nylon,
which gets weakened in the heat. Welding the clips with hot air is
feasible, but heating time, air flow profile and temperature profile is
quite critical. Ordinary hot air blowers will not do the job. Use a repair
station for soldering electronic surface mount devices, Weller (Model
WQB2000 finepitch/BGA repair) with a nozzle for SOP8.  A simple fixture
makes sure that the clip has the correct size to fit into the aluminum
rail.  Take a minimum of 3 minutes to heat up, then apply a heat peak to
both broken surfaces then press together -- done.
Heating the complete clip to slightly below the melting point seems also
to change the Nylon molecular constitution, and the welded clip appears
flexible as new.
	Thanks to all who contributed, the WWWeb is a wonderful thing!
	Bruce Browning – The Piano Tuner